Plant disease control by metabolites of fatty acids in bacteria
Abstract: Various metabolites of lipids produced by some bacteria from vegetable oil were shown to control bacterial and fungal plant disease, respectively. We focused on fatty acids produced as metabolites in culture. Cucumber plants were treated with supernatant (metabolite), water (as control), 2,4,5,6-tetrachloroisophthalonitrile (TPN), sorbitan fatty acid ester (PS) or potassium bicarbonate (PBC) and inoculated with Botrytis cinerea. In control, PS and PBC treatments symptoms of browning or holes were observed on each leaf. In treatments with the supernatant and TPN no remarkable symptoms were observed. In Arabidopsis thaliana, roots were treated with the supernatant, medium and control (water) and Erwinia carotovora was inoculated on above-ground parts of the plants. The treatment with each concentration of supernatant reduced the diseased foliage area by 71.4 to 93.0% compared to the control (water). These results indicated that the mechanism of disease control by metabolites from fatty acids was induced systemic resistance.